How the Sunk Cost Fallacy Can Drive Bad Decisions
The more we’ve invested in past decisions, the more reluctant we are to bail out. But we can correct this bias by counting the costs of staying on course.
By Elizabeth Svoboda
It was a Words with Friends chat that first gave Megan Phelps-Roper pause.
Along with much of her family, Phelps-Roper belonged to the infamous Westboro Baptist Church, a cult-like sect that spreads hateful messages about gay and transgender people. But in online conversations with her Words with Friends opponent, C.G., Phelps-Roper began to see the church through his eyes and recognize its cruelty, which led to still more questioning. “Little by little,” she wrote in her memoir, Unfollow, “my trust was eroding and withering.”
Even so, Phelps-Roper recoiled at the prospect of leaving Westboro. Not only had she put countless hours into helping it thrive over the years, she’d invested deeply in relationships with family and friends. When she thought about losing this community, she wrote, “there was no containing the despair and devastation that seized my body.”
People have a marked tendency to cling to past investments, whether financial, social, or emotional—even when it becomes clear that giving up those investments is the better move. Researchers call this the “sunk cost fallacy.”
“Humans want to be seen as consistent,” says Snow College psychologist and sunk cost researcher Veronika Tait. “Changing course feels like we have to admit we’ve made a mistake. It’s easier sometimes to double down.” At times, this fallacy warps moral decision making as people suppress their core values to justify the course they’ve locked on to.
Yet we can learn to recognize and offset sunk cost bias when it crops up. One way to correct it is to acknowledge the costs of staying on course and follow up with a blank-slate inquiry: Given the facts at hand, what would you decide if you’d never made a particular investment to begin with?
Sinking ever deeper
Long studied in the economic realm, the sunk cost fallacy relates to another very basic human tendency: our fear of loss. When researchers ask people why they keep making doomed investments, they often mention that they dislike the thought of waste. Cutting bait would mean acknowledging all their past efforts were for naught.
It makes sense, then, that we grow more prone to the sunk cost fallacy the larger our initial investment gets. Tait surveyed more than 100 people in one of her studies, asking them to describe how they’d respond in various sunk cost scenarios: driving to a park for a hike only to find it’s turned cold and rainy, or investing time and effort in a sport, then realizing they liked a different sport better. She found that the more people had given up to pursue a particular course, the more they chose to stay on that course even when it was doomed.
That rings true for ophthalmologist Gregg Feinerman, who invested more than $250,000 a few years ago on a new laser surgery platform for his practice. He believed it would ensure better vision correction and faster healing for his patients. Though that didn’t turn out to be the case, Feinerman stuck with the new system for months, telling himself he just needed to get the hang of it.
“It was the financial and emotional investment that made me persevere longer than I ought to,” he says. “I was convinced that with more time in the use of these lasers, my outcomes would eventually match my expectations.”
Though the cost of Feinerman’s persistence was mostly financial, sunk cost bias can breed disaster in other cases. After the airplane company Boeing clung to an ill-advised decision to refurbish flawed 737 planes instead of building new ones, two of the made-over planes crashed, claiming hundreds of lives.
How sunk costs can alter moral decision making
As in the Boeing scenario, sunk cost biases can nudge people or groups into corrupt decisions they never imagined they’d make. In a University of Waterloo study, researchers asked hundreds of people how they would respond in sunk cost situations with the potential for moral compromise.
Some participants, for instance, imagined they were medical researchers who’d conducted deadly experiments on 900 monkeys to develop a disease cure. After learning another company had come up with a cheaper, more effective cure, they were asked whether they would bail out—or needlessly kill another 100 monkeys to finish developing their own cure. People were more willing to take the futile, immoral step of killing 100 monkeys when they’d incurred the large sunk cost of having killed 900 already.
To get at some of the reasons for this, the researchers presented people with the same sunk cost scenarios and asked them how morally acceptable they would rate decisions to continue on a futile course. Overall, people said staying the course was more acceptable when there was a sunk cost involved. That suggested they were prone to alter their moral judgment to justify a choice they’d strongly invested in.
Since these sunk cost scenarios were hypothetical, says University of Waterloo psychologist Ori Friedman, they may not reflect exactly what would happen in real life. Some people, however, do seem willing to denounce formerly stated values in order to stay on a certain course.
“Changing course feels like we have to admit we’ve made a mistake. It’s easier sometimes to double down”
― Veronika Tait, Ph.D.
Before joining the Trump administration, podcaster Kash Patel advocated for exposing powerful people involved in Jeffrey Epstein’s sexual crimes. But after Trump named him the FBI director, Patel—apparently determined not to jeopardize the career path he’d chosen—started defending the government’s failure to release the Epstein files.
Doubling down on a choice can prompt an ongoing (and even escalating) series of moral compromises, in part because for some people, these compromises are easier to stomach than admitting their central choice was wrong or misguided. And regardless of the moral cost of staying on course, backtracking can be fiendishly difficult when doing so threatens entrenched social ties.
“The more we advocate for a certain position, the more we integrate ourselves in certain groups. Those are investments of time, effort, community, relationships,” Tait says. “It can be hard to change course when we have so much that we feel we have to justify.”
How to counterbalance sunk cost bias
Past investments of money, time, and social capital can warp present-day decisions in insidious ways. But assessing the true cost of those investments can give you greater clarity about the best choices to make in the present—moral, financial, and otherwise.
To help clients overcome sunk cost biases that keep them stuck, marriage and family therapist Kaila Hattis guides them to name what they’re giving up by remaining on a doomed course. One of her clients figured out that staying in a certain relationship was costing them about three hours of sleep every night, as well as hundreds of dollars in anxiety supplements and therapy appointments. Accounting for those losses helped the client see the relationship as “an experience in life and not a debt to be paid,” Hattis says, freeing them to move on without guilt.
Research suggests that recognizing distinct costs can help us pull out of a sunk cost mire. In one Canadian study where people considered what they’d do in a series of scenarios, they often showed sunk cost bias to some degree, persisting in doomed ventures they’d invested in.
However, they were more willing to bail out of what looked like a bad bet when they thought someone might be harmed if they continued. If, for instance, they’d spent $50 on movie tickets and the film became too scary for a niece or nephew, many said they’d leave rather than keep their young charges frozen in terror.
Even when we face the costs of sunk cost thinking, it can be hard to dislodge in cultures like ours, where perseverance is coded as strength and vacillation as weakness. Balanced assessment requires rejecting social norms that frame nuanced thinking as suspect.
“For us to learn new information and update our beliefs, it does require intellectual humility,” Tait says. “In politics, we see criticism of people that are flip-floppers—we don’t want them to be wishy-washy. But sometimes the rational thing is to change course.”
If you’re evaluating a longtime path or stance that no longer seems quite right, Tait recommends asking yourself a crystallizing question. “Just consider, ‘Would I still be making this choice if I hadn’t made that investment?’” she says. “Regardless of how much you’ve invested, focus on what’s going to be best moving forward.”
After months of inner struggle, Phelps-Roper chose that present-focused approach, leaving Westboro Baptist Church to build a new life in South Dakota. Though she had to sacrifice relationships she’d invested in, she gained what she sees as more important: the courage to live out her own values rather than those of corrupt leaders, and the humility to abandon a doomed course before it sinks her.